linux-kernel - Re: [PATCH v5 2/3] firmware: zynqmp: Add documentation for runtime feature config

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Message-ID: <d73c3b2d-2b46-4921-beff-fe7843f22325@xilinx.com>
Date:   Wed, 9 Feb 2022 10:29:37 +0100
From:   Michal Simek <michal.simek@...inx.com>
To:     Ronak Jain <ronak.jain@...inx.com>, <michal.simek@...inx.com>,
        <linux-kernel@...r.kernel.org>
CC:     <gregkh@...uxfoundation.org>, <rajan.vaja@...inx.com>,
        <corbet@....net>, <linux-arm-kernel@...ts.infradead.org>,
        <arnd@...db.de>, <lakshmi.sai.krishna.potthuri@...inx.com>
Subject: Re: [PATCH v5 2/3] firmware: zynqmp: Add documentation for runtime
 feature config



On 2/9/22 09:27, Ronak Jain wrote:
> Add documentation for sysfs entries like feature_config_id and
>   feature_config_value for runtime feature configuration. The support is
>   added for an over temperature and external watchdog features.
> 
> Signed-off-by: Ronak Jain <ronak.jain@...inx.com>
> ---
> Changes in v5:
> - Update kernel version for sysfs documentation
> 
> Changes in v4:
> - Add separate sysfs entries for runtime feature config
> - Update commit message
> 
> Changes in v3:
> - None
> 
> Changes in v2:
> - Update commit message
> ---
>   .../ABI/stable/sysfs-driver-firmware-zynqmp   | 141 ++++++++++++++++++
>   1 file changed, 141 insertions(+)
> 
> diff --git a/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp b/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp
> index f5724bb5b462..c3fec3c835af 100644
> --- a/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp
> +++ b/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp
> @@ -113,3 +113,144 @@ Description:
>   		    # echo 0 > /sys/devices/platform/firmware\:zynqmp-firmware/health_status
>   
>   Users:		Xilinx
> +
> +What:		/sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +Date:		Feb 2022
> +KernelVersion:	5.18
> +Contact:	"Ronak Jain" <ronak.jain@...inx.com>
> +Description:
> +		This sysfs interface allows user to configure features at
> +		runtime. The user can enable or disable features running at
> +		firmware as well as the user can configure the parameters of
> +		the features at runtime. The supported features are over
> +		temperature and external watchdog. Here, the external watchdog
> +		is completely different than the /dev/watchdog as the external
> +		watchdog is running on the firmware and it is used to monitor
> +		the health of firmware not APU(Linux). Also, the external
> +		watchdog is interfaced outside of the zynqmp soc.
> +
> +		The supported config ids are for the feature configuration is,
> +		1. PM_FEATURE_OVERTEMP_STATUS = 1, the user can enable or
> +		disable the over temperature feature.
> +		2. PM_FEATURE_OVERTEMP_VALUE = 2, the user can configure the
> +		over temperature limit in Degree Celsius.
> +		3. PM_FEATURE_EXTWDT_STATUS = 3, the user can enable or disable
> +		the external watchdog feature.
> +		4. PM_FEATURE_EXTWDT_VALUE = 4, the user can configure the
> +		external watchdog feature.
> +
> +		Usage:
> +
> +		Select over temperature config ID to enable/disable feature
> +		# echo 1 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +
> +		Check over temperature config ID is selected or not
> +		# cat /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +		The expected result is 1.
> +
> +		Select over temperature config ID to configure OT limit
> +		# echo 2 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +
> +		Check over temperature config ID is selected or not
> +		# cat /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +		The expected result is 2.
> +
> +		Select external watchdog config ID to enable/disable feature
> +		# echo 3 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +
> +		Check external watchdog config ID is selected or not
> +		# cat /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +		The expected result is 3.
> +
> +		Select external watchdog config ID to configure time interval
> +		# echo 4 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +
> +		Check external watchdog config ID is selected or not
> +		# cat /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +		The expected result is 4.
> +
> +Users:		Xilinx
> +
> +What:		/sys/devices/platform/firmware\:zynqmp-firmware/feature_config_value
> +Date:		Feb 2022
> +KernelVersion:	5.18
> +Contact:	"Ronak Jain" <ronak.jain@...inx.com>
> +Description:
> +		This sysfs interface allows to configure features at runtime.
> +		The user can enable or disable features running at firmware.
> +		Also, the user can configure the parameters of the features
> +		at runtime. The supported features are over temperature and
> +		external watchdog. Here, the external watchdog is completely
> +		different than the /dev/watchdog as the external watchdog is
> +		running on the firmware and it is used to monitor the health
> +		of firmware not APU(Linux). Also, the external watchdog is
> +		interfaced outside of the zynqmp soc.
> +
> +		By default the features are disabled in the firmware. The user
> +		can enable features by querying appropriate config id of the
> +		features.
> +
> +		The default limit for the over temperature is 90 Degree Celsius.
> +		The default timer interval for the external watchdog is 570ms.
> +
> +		The supported config ids are for the feature configuration is,
> +		1. PM_FEATURE_OVERTEMP_STATUS = 1, the user can enable or
> +		disable the over temperature feature.
> +		2. PM_FEATURE_OVERTEMP_VALUE = 2, the user can configure the
> +		over temperature limit in Degree Celsius.
> +		3. PM_FEATURE_EXTWDT_STATUS = 3, the user can enable or disable
> +		the external watchdog feature.
> +		4. PM_FEATURE_EXTWDT_VALUE = 4, the user can configure the
> +		external watchdog feature.
> +
> +		Usage:
> +
> +		Enable over temperature feature
> +		# echo 1 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +		# echo 1 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_value
> +
> +		Check whether the over temperature feature is enabled or not
> +		# cat /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_value
> +		The expected result is 1.
> +
> +		Disable over temperature feature
> +		# echo 1 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +		# echo 0 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_value
> +
> +		Check whether the over temperature feature is disabled or not
> +		# cat /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_value
> +		The expected result is 0.
> +
> +		Configure over temperature limit to 50 Degree Celsius
> +		# echo 2 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +		# echo 50 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_value
> +
> +		Check whether the over temperature limit is configured or not
> +		# cat /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_value
> +		The expected result is 50.
> +
> +		Enable external watchdog feature
> +		# echo 3 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +		# echo 1 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_value
> +
> +		Check whether the external watchdog feature is enabled or not
> +		# cat /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_value
> +		The expected result is 1.
> +
> +		Disable external watchdog feature
> +		# echo 3 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +		# echo 0 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_value
> +
> +		Check whether the external watchdog feature is disabled or not
> +		# cat /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_value
> +		The expected result is 0.
> +
> +		Configure external watchdog timer interval to 500ms
> +		# echo 4 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_id
> +		# echo 500 > /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_value
> +
> +		Check whether the external watchdog timer interval is configured or not
> +		# cat /sys/devices/platform/firmware\:zynqmp-firmware/feature_config_value
> +		The expected result is 500.
> +
> +Users:		Xilinx


Acked-by: Michal Simek <michal.simek@...inx.com>

Thanks,
Michal